[HDFS-dev] [jira] [Created] (HDFS-2093) 1073: Handle case where an entirely empty log is left during NN crash

1073: Handle case where an entirely empty log is left during NN crash
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Key: HDFS-2093
URL: https://issues.apache.org/jira/browse/HDFS-2093
Project: Hadoop HDFS
Issue Type: Sub-task
Components: name-node
Affects Versions: Edit log branch (HDFS-1073)
Reporter: Todd Lipcon
Assignee: Todd Lipcon
Fix For: Edit log branch (HDFS-1073)

Attachments: hdfs-2093.txt, hdfs-2093.txt, hdfs-2093.txt, hdfs-2093.txt


In fault-testing the HDFS-1073 branch, I saw the following situation:
- NN has two storage directories, but one is in failed state
- NN starts to roll edits logs to edits_inprogress_5160285
- NN then crashes
- on restart, it detects the truncated log, but since it has 0 txns, it finalizes it to the nonsense log name edits_5160285-5160284.
- It then starts logs again at edits_inprogress_5160285.
- After this point, no checkpoints or future NN startups succeed since there are two logs starting with the same txid